1. Field of the Invention
This invention generally relates to vehicle protection and occupant safety during a collision, and more specifically to a rib-reinforced “customized” or “tunable” energy absorber that absorbs energy imparted by an object that impacts the absorber or by a structure to which the absorber is affixed when it impacts an object.
2. Background Art
There are various ways to protect a vehicle and its occupants when the vehicle hits a wall or pedestrian, or an occupant impacts the A and B pillars, headliner, door, knee bolster, or any hard structure during an impact. The absorber may, for example, be positioned in a vehicle headliner, door panel, knee bolster, or bumper, in an A-pillar, B-pillar, or in other locations. Generally, the energy absorber is positioned (e.g., in a bumper or in a headliner) between a vehicle or its occupant and an incident force. It serves to at least partially cushion a blow and thus protect the vehicle or its occupant from severe injury. Illustrative approaches are described in U.S. Pat. No. 6,443,513, which issued on Sep. 3, 2002 to Glance, and in commonly owned U.S. Pat. Nos. 6,247,745; 6,199,942; 6,679,967; 6,682,128; 6,752,450.
Thermoformed energy absorbers as described, for example, in U.S. Pat. Nos. 6,017,084 and 6,752,450 describe geometric variations of thermoformed shapes. These shapes provide dynamic force versus deflection curves that essentially produce a “square wave” relationship of force and deflection.
In these and related approaches, there remains the desire to absorb as much impact energy in as little crush distance as possible, with as little absorber weight as possible, yet be capable of being designed and manufactured under favorable economic conditions.